In exemplary embodiments, the methods and compositions herein provide multifunctional boronic crosslinkers having low boronic acid content that may act as viscosification agents and/or friction reducing agents in fluids.
Many industrial applications require viscosified fluids that do not suffer from substantial friction reduction when pumped through tubulars, such as into a subterranean formation. Such industrial applications may include subterranean operations requiring treatment fluids having such properties for use in operations including, but not limited to, drilling operations, lost circulation operations, stimulation operations, acidizing operations, acid-fracturing operations, sand control operations, completion operations, scale inhibiting operations, water-blocking operations, clay stabilizer operations, fracturing operations, frac-packing operations, gravel packing operations, wellbore strengthening operations, sag control operations, and the like.
Traditionally, the treatment fluids are viscosified by use of a gelling agent. Common gelling agents include biopolymers or synthetic polymers, such as galactomannan gums, cellulosic polymers, and polysaccharides. Many viscosified treatment fluids further comprise a crosslinking agent capable of increasing the gelling agents' ability to impart viscosity to the fluid. These crosslinking agents typically comprise a metal ion, transition metal, or metalloid (collectively referred to herein as “metal(s)”). Examples include boron, aluminum, antimony, zirconium, magnesium, or titanium. Generally, the metal of a crosslinking agent interacts with at least two gelling agent molecules to form a crosslink between them, thereby forming a crosslinked gelling agent. These metal crosslinking agents have traditionally been placed into treatment fluids at high concentrations with a high concentration of gelling agents to ensure that the desired viscosity of the treatment fluid is reached and maintained over time. Such high concentrations may lead to increased costs and may also make the treatment fluid difficult to handle in certain circumstances (e.g., removal from a subterranean formation).
Subterranean operations often require large amounts of treatment fluids to be pumped downhole under high pressures and high flow rates in short periods of time, causing turbulent flow of the treatment fluids, even in viscous treatment fluids. The turbulence results in friction pressure between the treatment fluid and the subterranean operations equipment (e.g., wellbore piping, wellbore casing, etc.) and between the treatment fluid and the subterranean formation itself. The friction pressure increases the energy necessary to pump the treatment fluid downhole and can cause damage to subterranean operation equipment and the formation. To combat the friction pressure, friction reducing agents are often added to treatment fluids already comprising gelling agents and crosslinkers. Traditional friction reducing agents are high molecular weight, long-chain polymers (e.g., polyacrylamide) that are able to change the rheological properties of the treatment fluid to overcome or minimize friction pressure. High molecular weight, long-chain friction reducing polymers are capable of converting turbulent flow to laminar flow, thereby reducing frictional drag and pressure loss. Traditional friction reducing polymers tend to be characterized by a large hydrodynamic radius such that upon shearing, the friction reducing polymers can absorb energy from high nucleation sites by stretching to a more relaxed form and redistribute the energy to other locales.